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Ultrahigh-efficiency second-harmonic generation in nanophotonic PPLN waveguides

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 نشر من قبل Mian Zhang
 تاريخ النشر 2018
  مجال البحث فيزياء
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Periodically poled lithium niobate (PPLN) waveguide is a powerful platform for efficient wavelength conversion. Conventional PPLN converters however typically require long device lengths and high pump powers due to the limited nonlinear interaction strength. Here we use a nanostructured PPLN waveguides to demonstrate an ultrahigh normalized efficiency of 2600%/W-cm$^2$ for second-harmonic generation of 1.5-$mu$m radiation, more than 20 times higher than that in state-of-the-art diffused waveguides. This is achieved by a combination of sub-wavelength optical confinement and high-fidelity periodic poling at a first-order poling period of 4 $mu$m. Our highly integrated PPLN waveguides are promising for future chip-scale integration of classical and quantum photonic systems.



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